try {    Intent a = getPackageManager().getLaunchIntentForPackage("com.tencent.mobileQQ");    startActivity(a);}catch (Exception e){    Toast.makeText(MainActivity.this,"打開失敗",Toast.LENGTH_SHORT).show();;
}
Intent a = getPackageManager().getLaunchIntentForPackage("com.tencent.mm"); startActivity(a);